Methods and systems for venting pipelines

Abstract

This disclosure relates to methods and systems for bleed lines. Methods and systems for closely coupled aftertreatment devices are provided. In one example, the system may include an engine including separate first and second main exhaust lines, wherein the bleed line branches off from the second main exhaust line, and wherein a closely coupled aftertreatment device is arranged in the bleed line and configured to receive exhaust gas at least during a cold start of the engine.

Description

[0001] Cross-application of related applications

[0002] This application claims priority to German Patent Application No. 102017209741.8, filed on June 9, 2017. The entire contents of the above-cited application are incorporated herein by reference in their entirety for all purposes. Technical Field

[0003] This disclosure relates to adjusting the exhaust valve operation of the first and second exhaust valves of an engine cylinder, wherein the adjustment is responsive to a cold start. Background Technology

[0004] The type of internal combustion engine is used as a drive unit for motor vehicles. In the context of this disclosure, the term "internal combustion engine" may encompass both Otto cycle engines and hybrid internal combustion engines that utilize a hybrid combustion process with applied ignition and a hybrid drive that includes not only the applied ignition of the internal combustion engine but also an electric motor that may be connected to and receive power from the internal combustion engine for drive purposes, or that additionally outputs power as a switchable auxiliary drive.

[0005] An internal combustion engine may include a cylinder block and at least one cylinder head, which are connected to each other to form cylinders and their combustion chambers. As the upper part of the crankcase, the cylinder block is typically used to mount the crankshaft and house the pistons and cylinder liners for each cylinder.

[0006] The crankshaft, mounted in the crankcase, absorbs the connecting rod force and converts the piston's oscillating stroke motion into the crankshaft's rotational motion. The upper part of the crankcase, formed by the cylinder block, is usually supplemented by an oil pan, which can be mounted on the cylinder block and used as the lower part of the crankcase.

[0007] The cylinder head can accommodate valve actuation devices for charge exchange. During the charge exchange process, combustion gases are emitted through the exhaust system via outlet openings, and boosted air is fed through the intake system via inlet openings of at least two cylinders.

[0008] Each lift valve movement is performed to achieve (i.e. execute) the maximum valve lift between the open and closed positions, and in doing so, the valve-specific opening is maintained for a certain duration during the opening process. The valve actuation mechanism (including the valve itself) for which the valve movement is desired is called the valve drive.

[0009] The valve actuation mechanism opens and closes and / or shuts off the inlet and outlet openings at the correct time, rapidly opening the maximum possible flow cross-section to keep the throttling losses of the inflow and outflow gases low, thereby ensuring improved cylinder charging and efficient exhaust. Therefore, a cylinder may be provided with two or more inlet and outlet openings.

[0010] The internal combustion engine disclosed herein is equipped with at least two cylinders having at least one inlet opening and at least two outlet openings.

[0011] According to the previous example, the intake line leading to the inlet opening and the exhaust line adjacent to the outlet opening are at least partially integrated in the cylinder head. The cylinder exhaust lines may be merged to form a common main exhaust line, or grouped to form two main exhaust lines, as in the internal combustion engine according to this disclosure. The merging of exhaust lines to form a main exhaust line is referred to as an exhaust manifold, wherein, in the context of this disclosure, the main exhaust line is considered part of the exhaust manifold.

[0012] For boosting purposes, exhaust gas may be supplied downstream of the manifold to the turbine of at least one exhaust turbocharger and / or one or more exhaust aftertreatment systems. In some cases, the exhaust gas is recirculated back into the intake system.

[0013] In the case of the internal combustion engine disclosed herein, for turbocharging purposes, exhaust gas from the cylinders is supplied to the turbine of at least one exhaust turbocharger via a first main exhaust line, and exhaust aftertreatment is performed downstream of the turbine. A second main exhaust line connects the cylinders at the outlet side to the intake system upstream of the compressor of at least one exhaust turbocharger. Here, the cylinder exhaust lines are configured to form two groups, each group including at least one exhaust line from each cylinder, and the exhaust lines of each group are merged in each case of forming an exhaust manifold to form a main exhaust line.

[0014] This type of internal combustion engine and methods for operating such engines are described, for example, in German publication DE 10 2016 111 686 A1. In a variant of DE 10 2016 111 686 A1, a first set of exhaust gases may be introduced, for example, into the intake system downstream or upstream of the compressor of the exhaust turbocharger and / or fed to the turbine of the exhaust turbocharger, while a second set of exhaust gases may be introduced upstream of the compressor and / or fed to the turbine. Improved knock control and improved cylinder scavenging or purification with fresh air are sought, while maintaining a stoichiometric air-to-steam ratio during exhaust aftertreatment, when desired. The latter may involve exhaust aftertreatment (e.g., a three-way catalytic converter). Acceleration by the exhaust turbocharger can also be achieved via an increase in the gas throughput through the cylinders.

[0015] The advantage of an exhaust turbocharger over a supercharger driven by an auxiliary drive is that the exhaust turbocharger utilizes the exhaust energy of hot exhaust gases, while the supercharger draws the energy required to drive itself directly or indirectly from the internal combustion engine, thus negatively impacting efficiency—that is, efficiency is reduced at least as long as the driving energy does not originate from an energy recovery source. If the supercharger is not one that can be driven by an electric motor (i.e., electrically driven), mechanical or kinematic connections for power transmission can be arranged between the supercharger and the internal combustion engine, which can also negatively impact or define the encapsulation of the engine compartment.

[0016] An exhaust turbocharger includes a compressor and a turbine arranged on the same shaft. Hot exhaust gas is fed to the turbine and expands within it as energy is released, thereby rotating the shaft. The energy released from the exhaust gas to the turbine and ultimately to the shaft drives the compressor, also arranged on the shaft. The compressor delivers and compresses the boost air supplied to it, thereby achieving mechanical supercharging of at least two cylinders. A boost air cooling arrangement can be configured to cool the compressed boost air before it enters the cylinders.

[0017] Mechanical supercharging increases the power of an internal combustion engine. Here, the air used for combustion is compressed, allowing a larger mass of air to be supplied to each cylinder in each working cycle. In this way, the fuel mass is increased, and therefore the mean pressure is increased. Mechanical supercharging can increase the power of an internal combustion engine while maintaining a constant scavenging volume, or it can reduce the scavenging volume while maintaining the same power. In all cases, mechanical supercharging results in an increase in volumetric power output and a more favorable power-to-weight ratio. If the scavenging volume is reduced, the load can be shifted towards a higher load under the same vehicle boundary conditions, at which the specific fuel consumption rate is lower.

[0018] Mechanical supercharging thus helps to minimize the fuel consumption of internal combustion engines, i.e., improve the efficiency of internal combustion engines.

[0019] A suitable transmission configuration can provide speed reduction, thereby achieving a lower specific fuel consumption rate. With speed reduction, the specific fuel consumption rate is typically lower at low engine speeds, especially under relatively high loads.

[0020] With targeted configuration of mechanical supercharging, advantages can also be gained regarding exhaust emissions. For example, with appropriate mechanical supercharging of a diesel engine, nitrogen oxide emissions can be reduced without any loss of efficiency. Simultaneously, hydrocarbon emissions can be positively affected. Carbon dioxide emissions, directly related to fuel consumption, decrease in any case as fuel consumption decreases.

[0021] In order to meet future pollutant emission limits, additional measures besides mechanical supercharging are necessary, and for this reason, various exhaust aftertreatment systems for converting pollutants are typically used.

[0022] The internal combustion engine disclosed herein is equipped not only with a supercharger arrangement but also with an exhaust aftertreatment arrangement.

[0023] It is desirable to position the turbine of the exhaust turbocharger as close as possible to the cylinder outlet opening to maximize the utilization of the exhaust enthalpy of the hot exhaust (which is largely determined by exhaust pressure and temperature) and to allow for rapid turbine response behavior, and thus rapid turbocharger response behavior. Furthermore, close-coupling minimizes thermal inertia and the volume of the piping system between the cylinder outlet opening and the turbine, which can be achieved by reducing the mass and length of the exhaust lines. Integrating the exhaust manifold into the cylinder head facilitates this objective.

[0024] Various exhaust aftertreatment systems are expected to reach certain minimum temperatures in order to convert the corresponding pollutants; for this reason, exhaust aftertreatment systems should also be positioned in the most closely coupled possible locations. There is therefore a conflict of interest regarding the arrangement of the turbine and the exhaust aftertreatment system, where the turbine may be given higher priority, as is the case in the internal combustion engine of this disclosure.

[0025] Because of the relatively large distance covered by the exhaust from the exhaust valve outlet to the exhaust aftertreatment system, the conversion of pollutants during the exhaust aftertreatment process can be less than the threshold during cold starts, where the turbine acts as an additional temperature radiator or is considered an additional temperature radiator. Summary of the Invention

[0026] The inventors recognized the problems described above and have proposed methods to solve them, at least in part. In one example, a supercharged internal combustion engine has three cylinders arranged in an inline, each cylinder having at least one inlet opening for supplying pressurized air via an intake system and at least two outlet openings for discharging exhaust gas via an exhaust system, each outlet opening adjacent to an exhaust line. At least one exhaust turbocharger is provided, comprising a turbine arranged in the exhaust system and a compressor arranged in the intake system. The exhaust lines are configured to form two groups, each group comprising at least one exhaust line from each cylinder, and the exhaust lines of each group merge in each case of forming an exhaust manifold to form a main exhaust line. A first main exhaust line of the first group leads to the turbine of the at least one exhaust turbocharger, and a second main exhaust line of the second group leads to the intake system upstream of the compressor of the at least one exhaust turbocharger. At least one exhaust aftertreatment system is provided in the exhaust system downstream of the turbine of the at least one exhaust turbocharger. The internal combustion engine is distinguished by the fact that it can prevent exhaust gas from being discharged via the first main exhaust line and that a blow-off line is provided. The vent line has a cut-off element arranged in it, and the vent line branches off from the exhaust manifold of the second group as the first junction is formed, and leads to the exhaust system downstream of the turbine of at least one exhaust turbocharger as the second junction is formed, with an accumulator for unburned hydrocarbons provided in the vent line.

[0027] In the case of the internal combustion engine according to this disclosure, exhaust gas from the second set of exhaust manifolds can be transmitted through the exhaust turbocharger's turbine via a bleed line. An accumulator for unburned hydrocarbons is provided in the bleed line.

[0028] In one example, during the warm-up phase, especially during cold start, for exhaust gas to be treated in a closely coupled position, and as needed, unburned hydrocarbons in the exhaust gas are collected and stored in an accumulator configured according to this disclosure.

[0029] For this purpose, exhaust gas is prevented from being discharged through the first main exhaust line, i.e., by blocking it through shut-off elements in the exhaust gas discharge system upstream or downstream of the turbine. Alternatively, exhaust gas discharge through the first main exhaust line can be prevented by equipping the outlet openings of the first group with switchable valves. For example, the introduction of exhaust gas into the intake system can be stopped by closing a shut-off element located in the second main exhaust line.

[0030] By opening the cut-off element located in the vent line, the vent line is opened to exhaust gas originating from the second exhaust manifold, and the accumulator for unburned hydrocarbons is filled with exhaust gas.

[0031] The unburned hydrocarbons collected in the accumulator can then be released and oxidized again under other operating conditions. Preferably, the unburned hydrocarbons collected in the accumulator are introduced into the exhaust system along with the exhaust gas flowing through the vent line, and oxidized using a catalytic converter in the exhaust system.

[0032] Since no exhaust gas is discharged from the cylinders via the first main exhaust line during the warm-up phase, the outlet valves belonging to the second group of outlet openings can be actuated with regard to effective charge exchange. That is, the outlet openings of the second group can be opened to achieve maximum valve lift Δh in each case during the compression phase of the associated cylinder. max .

[0033] When the internal combustion engine is warmed up, and exhaust is primarily discharged from the cylinders via the first main exhaust line, the second set of outlet valves can be opened as needed to achieve maximum valve lift Δh in each case when the associated cylinder transitions from the compression phase to the expansion phase. max In some cases, the outlet valve of the second group is opened at the top dead center of the inflation exchange.

[0034] By doing so, emissions from internal combustion engines can be reduced.

[0035] As in previous examples, exhaust lines for three-cylinder inline engines are rarely grouped because three-cylinder inline engines can be difficult to group, especially cylinder grouping. However, the exhaust lines are merged according to this disclosure, thus avoiding these problems.

[0036] The internal combustion engine according to the example has exactly three cylinders arranged in an inline. Therefore, the internal combustion engine according to this disclosure is a three-cylinder inline engine.

[0037] Embodiments of a supercharged internal combustion engine may also include each cylinder having at least two inlet openings for supplying boosted air via an intake system.

[0038] By providing a large flow cross-section, the throttling loss of the incoming boost air can be kept low, and the desired charge of the cylinder can be maintained. Therefore, it is desirable for the cylinder to be equipped with more than one inlet opening, i.e., having at least two inlet openings.

[0039] Based on similar considerations, embodiments of a turbocharged internal combustion engine may further include each cylinder having three outlet openings for discharging exhaust gas via an exhaust system, with exhaust lines from two outlet openings of each cylinder collectively forming a first set of exhaust manifolds. This allows for efficient exhaust gas discharge during the charge-exchange process.

[0040] During normal operation of an internal combustion engine during warm-up (e.g., excluding cold starts), the cylinders are primarily vented through the outlet openings or the first set of exhaust lines. That is, the main exhaust portion is discharged from the cylinders via the first master exhaust line and the first set of exhaust valves.

[0041] The exhaust lines with the two outlet openings of each cylinder can together form the first set of exhaust manifolds, i.e., leading to the first main exhaust line. Then, in particular, the larger inlet cross-section, especially the two outlet openings, is configured for the exhaust path via the first main exhaust line.

[0042] For the reasons mentioned above, embodiments of the supercharged internal combustion engine are also advantageous, wherein the diameter of the outlet opening of the first group of exhaust lines is larger than the diameter of the outlet opening of the second group of exhaust lines.

[0043] In this embodiment of the outlet opening, a larger inlet cross-section is distributed to the exhaust path via a first main exhaust line, wherein the diameter of the outlet opening is larger.

[0044] Embodiments of a supercharged internal combustion engine may include an exhaust line leading to an exhaust aftertreatment system located upstream of an exhaust exhaust system as a second junction is formed.

[0045] If the vent line opens with the exhaust gas flowing through it, the unburned hydrocarbons collected in the accumulator can be released again. The released unburned hydrocarbons enter the exhaust emission system at the second junction along with the exhaust gas, and can, under current conditions, be converted or oxidized in the exhaust aftertreatment system located downstream of the second junction. This is desirable when the exhaust aftertreatment system used is a three-way catalytic converter.

[0046] However, the vent line can also be connected to an exhaust system downstream of the exhaust aftertreatment system in the exhaust system, or between two exhaust aftertreatment systems, which can be of the same type, such as two three-way catalytic converters, with the formation of the second junction.

[0047] Embodiments of a supercharged internal combustion engine may include an exhaust system in which a cut-off element is disposed between the turbine and a second engagement point of at least one exhaust turbocharger to prevent exhaust emissions via a first main exhaust line.

[0048] Embodiments of a turbocharged internal combustion engine may also include an exhaust discharge system in which a cut-off element is disposed upstream of the turbine of at least one exhaust turbocharger to prevent exhaust gas from being discharged via a first main exhaust line.

[0049] The above embodiments may use a cut-off element for adjusting exhaust emissions via a first main exhaust line, wherein the cut-off element may be located or will be located in the exhaust emission system upstream of the turbine or between the turbine and the second junction.

[0050] Embodiments of a supercharged internal combustion engine may include an outlet opening belonging to a first set of exhaust lines each equipped with at least partially variable-actuated outlet valves, wherein the outlet valves can be deactivated for the purpose of shutting off the associated outlet openings and preventing exhaust from being discharged via a first main exhaust line.

[0051] Embodiments of a supercharged internal combustion engine may include a cut-off element disposed in a second main exhaust line downstream of the first junction.

[0052] When exhaust gas originating from the cylinder is discharged via the bleed line and exhaust gas is prevented (i.e. stopped) from being discharged via the first main exhaust line, the introduction of exhaust gas into the intake system can be stopped by closing the shut-off element located in the second main exhaust line.

[0053] The cut-off element installed in the second main exhaust line can adjust the recirculation rate of the exhaust recirculation arrangement.

[0054] Embodiments of a supercharged internal combustion engine may include a cooler disposed in a second main exhaust line downstream of the first junction.

[0055] To reduce nitrogen oxide emissions, the second main exhaust line can be used for the recirculation of combustion gases from the outlet side to the inlet side (i.e., in the case of exhaust gas recirculation). To achieve a substantial reduction in nitrogen oxide emissions, a high exhaust gas recirculation rate is desirable, the magnitude of which can be approximately x. EGR ≈60% to 70% or greater. Such high recirculation rates are expected to cool the exhaust gas for recirculation, where the exhaust gas temperature is reduced and the exhaust gas density is increased, allowing for the recirculation of a larger mass of exhaust gas. Therefore, the exhaust gas recirculation arrangement can be equipped with a cooler. During the cooling process, condensate can form and settle in the cooler.

[0056] Embodiments of a supercharged internal combustion engine may include an intake system in which a boost air cooler is disposed downstream of the compressor of at least one exhaust turbocharger, wherein the boost air cooler cools the compressed boost air before it enters at least two cylinders. The cooler lowers the temperature and thus increases the density of the boost air, thereby also contributing to improved cylinder charging, i.e., achieving a larger air mass. In effect, compression occurs through cooling.

[0057] Embodiments of a supercharged internal combustion engine may include, for exhaust aftertreatment purposes, at least one three-way catalytic converter disposed downstream of the turbine of at least one exhaust turbocharger in the exhaust emission system.

[0058] To reduce pollutant emissions, internal combustion engines can be equipped with various exhaust aftertreatment systems. Even without additional measures, under sufficiently high temperature levels and in the presence of sufficiently large oxygen quantities, the oxidation of unburned hydrocarbons (HC) and carbon monoxide (CO) occurs sufficiently during the expansion and exhaust of the cylinder charge. However, the reaction can be rapidly stopped due to the rapidly decreasing exhaust temperature downstream and consequently, the rapidly decreasing reaction rate.

[0059] For these reasons, a catalytic converter is used, which allows HC and CO to be oxidized even at low temperatures by using catalytic materials that increase the rate of certain reactions. If additional reduction of nitrogen oxides is desired, this can be achieved using a three-way catalytic converter, which, for this purpose, utilizes the stoichiometric operation of an internal combustion engine within narrow constraints (λ≈1). Here, nitrogen oxides are reduced via present unoxidized exhaust components (particularly carbon monoxide and unburned hydrocarbons), which can be simultaneously oxidized.

[0060] In internal combustion engines that operate with excess air, nitrogen oxides in the exhaust cannot be reduced without introducing a reducing agent into the exhaust. To facilitate oxidation, an oxidation catalytic converter is then placed in the exhaust system.

[0061] Embodiments of a supercharged internal combustion engine may include a second exhaust valve corresponding to a second main exhaust line, each equipped with at least partially variable-actuated outlet valves that oscillate between an open position and a closed position to achieve maximum valve lift Δh. max And during the opening process, the associated outlet opening is opened for a duration Δt. max Furthermore, the opening process can be advanced and / or delayed.

[0062] During some operations of an internal combustion engine during warm-up, excluding cold starts, when all cylinder valves are active and actuated, the actuation of the second outlet valve can be performed to recirculate exhaust gas or gas to the intake system upstream of the compressor. Alternatively, the second outlet valve can be actuated in response to a load on an accumulator located in a bleed line branching from the second main exhaust line.

[0063] In contrast, during the warm-up phase and / or cold start, when no exhaust gas is being emitted from the cylinders via the exhaust system through the first main exhaust line, the outlet valves of the second group are correspondingly actuated for efficient exhaust gas exchange. That is, the second exhaust valve can open at a time similar to when the first exhaust valve opens outside of a cold start. For this purpose, the opening process of the second exhaust valve can be advanced during the cold start and / or warm-up phase. Specifically, the outlet opening of the second group opens earlier, particularly maximizing the maximum valve lift Δh. max This is achieved in each case during the compression phase of the gas exchange in the associated cylinder.

[0064] When the warm-up phase and / or cold start are complete, the opening process of the second exhaust valve can be delayed and the first exhaust valve can be activated. Then, the maximum valve lift Δh max In each case of the expansion phase of the intake exchange in the associated cylinder, or during the transition from the compression phase to the expansion phase, it may occur at top dead center of the intake exchange. In other words, the second exhaust valve may open as the piston transitions between the exhaust and intake strokes.

[0065] Embodiments of a supercharged internal combustion engine may include at least one exhaust turbocharger in which the turbine is in the form of an exhaust valve turbine, a bypass line branching off from the exhaust system upstream of the turbine, and a cut-off element disposed in the bypass line.

[0066] Embodiments of a supercharged internal combustion engine may include a turbine in at least one exhaust turbocharger having a variable turbine geometry that allows for wide adaptation to a given operating point by adjusting the turbine geometry or effective turbine cross-section. Here, guide vanes for influencing flow direction may be arranged upstream of the turbine impeller. Unlike the impeller blades of the rotating impeller, the guide vanes do not rotate with the turbine shaft, i.e., they do not rotate with the impeller. The guide vanes are arranged to be stationary but not completely immovable, but rather rotatable about their axis to influence flow approaching the impeller blades. Conversely, if the turbine has a fixed, immutable geometry, the guide vanes are not only stationary but also completely immovable; that is, if a guiding device is provided, the guide vanes are rigidly fixed.

[0067] Embodiments of a supercharged internal combustion engine may include merging the exhaust lines of at least two cylinders to form two main exhaust lines within the cylinder head.

[0068] The cylinder head of a supercharged internal combustion engine is essentially a component subjected to high thermal and mechanical loads. Specifically, with the integrated exhaust manifold, the thermal load on both the internal combustion engine and the cylinder head increases further, leading to increased demands on the cooling system. Embodiments of supercharged internal combustion engines incorporating liquid-cooled systems are desirable.

[0069] A method for operating a mechanically supercharged internal combustion engine of the type described above is implemented by means of: preventing exhaust gas from being discharged via a first main exhaust line after the internal combustion engine is started during the warm-up phase, and introducing exhaust gas originating from a second exhaust manifold into an exhaust gas discharge system downstream of the turbine of at least one exhaust turbocharger via a bleed line, wherein unburned hydrocarbons in the exhaust gas are collected and stored in an accumulator.

[0070] For operating a supercharged internal combustion engine in a second main exhaust line downstream of a first junction, variations of the method may include having the cut-off element remain closed during the warm-up phase to reduce exhaust gas recirculation flow. However, the cut-off element in the second main exhaust line can essentially be used during the warm-up phase to set the amount of exhaust gas recirculated into the intake system.

[0071] Variations of the method may also include opening the vent line once the internal combustion engine has warmed up, for the purpose of oxidizing the unburned hydrocarbons collected in the accumulator.

[0072] In this context, method variations may include the release of unburned hydrocarbons collected in the accumulator along with exhaust gas and their introduction into the exhaust emission system, whereby a three-way catalytic converter is used to oxidize the unburned hydrocarbons. As described above, by opening the second exhaust valve during charge exchange outside of a cold start, a sufficient amount of air and exhaust gas can flow through the accumulator to the three-way catalytic converter to oxidize the unburned hydrocarbons.

[0073] For operating a supercharged internal combustion engine in which each outlet opening is equipped with at least partially variable-actuated outlet valves, the outlet openings belonging to a second set of exhaust lines, the outlet valves oscillating between an open position and a closed position to achieve maximum valve lift Δh max During the opening process, the associated outlet opening is opened for a duration Δt. max Furthermore, the opening process can be advanced and / or delayed, and variations of the method may include opening the outlet valve belonging to the second group of outlet openings during the warm-up phase to achieve the maximum valve lift Δh. max This is achieved in each case during the compression phase of the associated cylinder.

[0074] In this context, method variations may include opening the outlet valves belonging to the second group of outlet openings when the internal combustion engine is warmed up, such that maximum valve lift Δh is achieved in each case during the transition from the compression phase to the expansion phase of the associated cylinder. max .

[0075] It should be understood that the above description of the invention is provided as a simplified presentation of the concepts further described in the detailed embodiments. This is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the appended claims. Furthermore, the claimed subject matter is not limited to embodiments that address any shortcomings mentioned above or in any part of this disclosure. Attached Figure Description

[0076] Figure 1A The first embodiment of a turbocharged internal combustion engine is schematically shown.

[0077] Figure 1B Showing features other than cold start Figure 1A The valve travel curve during the operation of an internal combustion engine.

[0078] Figure 1C It shows in Figure 1A Valve travel curves during the cold start and / or warm-up phases of an internal combustion engine.

[0079] Figure 2A A second embodiment of a supercharged internal combustion engine is schematically shown.

[0080] Figure 2B It shows in Figure 2A The valve travel curve during the warm-up phase of an internal combustion engine.

[0081] Figure 3A and Figure 3B A method for operating the exhaust valve of an engine during and outside of a cold start is shown.

[0082] Figure 4 A schematic diagram of the cylinders of an engine in a hybrid vehicle is shown. Detailed Implementation

[0083] The following description relates to a system and method for a mechanically supercharged internal combustion engine with three cylinders arranged in an inline and subject to ignition. Each cylinder of the internal combustion engine has at least one inlet opening for supplying pressurized air via an intake system and at least two outlet openings for discharging exhaust gas via an exhaust system. Each outlet opening is adjacent to an exhaust line. At least one exhaust turbocharger is provided, comprising a turbine arranged in the exhaust system and a compressor arranged in the intake system. The exhaust lines are arranged to form two groups, each group comprising at least one exhaust line from each cylinder. The exhaust lines of each group are merged in each case of forming an exhaust manifold to form a total exhaust line. A first total exhaust line of the first group leads to the turbine of at least one exhaust turbocharger, and a second total exhaust line of the second group leads to the intake system upstream of the compressor of at least one exhaust turbocharger. At least one exhaust aftertreatment system is provided in the exhaust system downstream of the turbine of at least one exhaust turbocharger. This disclosure also relates to a method for operating an internal combustion engine of the type described above, particularly during the warm-up phase after the internal combustion engine has been started.

[0084] A first embodiment of the engine may include three cylinders arranged in an inline configuration, each of which includes four valves: two intake valves and two exhaust valves. The exhaust valves may be fluidly coupled to separate exhaust lines, with a first set of first exhaust valves fluidly coupled to a first main exhaust line and a second set of second exhaust valves fluidly coupled to a second exhaust line. In one example, the first main exhaust line may be a higher-pressure exhaust line including a turbine, and the second main exhaust line may be a lower-pressure exhaust line configured to provide low-pressure exhaust to the intake system. A bleed line may branch off from a portion of the second main exhaust line, wherein the bleed line may include an accumulator, which is activated to store hydrocarbons below a lower threshold temperature. The bleed line and the first main exhaust line may merge downstream of the accumulator to form a third main exhaust line including at least one three-way catalyst. The third main exhaust line may conduct exhaust gases to the ambient atmosphere. Figure 1A The first embodiment is shown in the figure.

[0085] Figure 1B The diagram illustrates the valve timing of the first and second exhaust valves, excluding cold start conditions, in a first embodiment of the engine. The first exhaust valve is used to expel exhaust gas, while the second exhaust valve can be actuated to provide exhaust gas recirculation and / or release hydrocarbons trapped on the accumulator. More specifically, the release of hydrocarbons trapped on the accumulator can occur only outside of engine boost conditions. However, exhaust gas recirculation can occur both during and outside of boost conditions.

[0086] Figure 1C The valve timing of the first and second exhaust valves is shown during a cold start of the engine in a first embodiment. The actuator can keep the first exhaust valve closed and the second exhaust valve can be used to expel exhaust gas.

[0087] Figure 2A It shows Figure 1A The second embodiment of the engine is shown. The difference between the second and first embodiments may be that the first exhaust valve does not include an actuator configured to keep the first exhaust valve closed. Therefore, during a cold start of the second embodiment of the engine, the first exhaust valve can continue to oscillate between the open and closed positions, as... Figure 2B As shown. However, the first main exhaust line of the second embodiment may include a shut-off element (e.g., a valve) shaped to prevent exhaust from flowing from the first main exhaust line to its turbine and third main exhaust line.

[0088] Figure 3A and Figure 3B A method for operating the first and second exhaust valves during and outside of a cold start is shown. Figure 4 A schematic diagram of a single cylinder of an engine in a hybrid vehicle is shown.

[0089] Now go to Figure 1A This illustration shows a first embodiment 100 of a mechanically supercharged internal combustion engine 10 equipped with an exhaust turbocharger 8. The exhaust turbocharger 8 includes a turbine 8a arranged in an exhaust system 5 and a compressor 8b arranged in an intake system 3. Hot exhaust gas expands in the turbine 8a, releasing energy, thereby rotating the shaft of the exhaust turbocharger 8. The energy released by the exhaust flow to the turbine 8a and ultimately to the shaft is used to drive the compressor 8b, which is also arranged on the shaft. The compressor 8b compresses the gas flowing through it and conducts the compressed boosted air to the cylinder 1 via the intake system 3, in which a boosted air cooler 14 and a throttling element 15 are arranged, thereby achieving mechanical supercharging of the internal combustion engine 10.

[0090] Each of the turbine 8a and compressor 8b may be equipped with a corresponding bypass and bypass valve. More specifically, turbine 8a may include a turbine bypass 9, which includes a turbine bypass element 9a. Similarly, compressor 8b may include a compressor bypass 9b, which includes a compressor bypass element 9c. In cases where a smaller pressure boost is desired or no pressure boost is desired, each of the turbine bypass element 9a and compressor bypass element 9c may then be actuated to an open position to allow gas to flow around turbine 8a and compressor 8b, respectively.

[0091] The internal combustion engine 10 may be a three-cylinder in-line engine 10, wherein the three cylinders 1 are arranged along the longitudinal axis of the cylinder head, i.e., in a straight line. Each cylinder 1 has two inlet openings 2a, 2b for supplying pressurized air via the intake system 3, and two outlet openings 4a, 4b respectively adjacent to exhaust lines 5a and 5b for discharging exhaust gas via the exhaust system 5. It should be understood that the engine 10 may include other configurations in a manner well known to those skilled in the art. For example, the engine 10 may be a V6 engine, wherein the three cylinders 1 are cylinders of a first group of cylinders, and wherein the second group of cylinders of the V6 engine also includes three cylinders similar to cylinders 1.

[0092] Exhaust lines 5a and 5b are configured to form two groups, each group comprising one exhaust line 5a and 5b from each cylinder 1. In each case of forming an exhaust manifold, exhaust lines 5a and 5b of each group are merged to form main exhaust lines 6a and 6b, wherein the exhaust line 5a adjacent to the first cylinder-dedicated outlet opening 4a is merged to form a first main exhaust line 6a, and the exhaust line 5b adjacent to the second cylinder-dedicated outlet opening 4b is merged to form a second main exhaust line 6b. In this document, the first cylinder-dedicated outlet opening 4a may be interchangeably referred to as the first exhaust valve 4a, and the second cylinder-dedicated outlet opening 4b may be referred to as the second exhaust valve 4b.

[0093] In other words, the first exhaust valve 4a fluidly couples three cylinders 1 to exhaust line 5a, which merges to form a first main exhaust line 6a. The second exhaust valve 4b fluidly couples three cylinders 1 to exhaust line 5b, which merges to form a second main exhaust line 6b. The first main exhaust line 6a and the second main exhaust line 6b are fluidly separated. In one example, the gas in the first main exhaust line 6a does not contain the gas in the second main exhaust line 6b and does not mix with the gas in the second main exhaust line 6b.

[0094] The first exhaust manifold 6a directs gas flow to the turbine 8a, while the second exhaust manifold 6b directs gas flow to the intake system 3 upstream of the compressor 8b as low-pressure exhaust gas recirculation. Therefore, the first exhaust manifold 6a can be a higher-pressure exhaust manifold, while the second exhaust manifold 6b can be a lower-pressure exhaust manifold. During certain engine conditions where LP-EGR is desired, the second exhaust manifold 6b can receive higher-pressure exhaust gas based on the valve timing of the second exhaust valve 4b.

[0095] The vent line 7 branches off from the second main vent line 6b at the first junction 7b. The vent line 7 may also include an accumulator 12 upstream of a first shut-off element 7a, which may be a pneumatically actuated, mechanically actuated, electrically actuated, and / or hydraulically actuated valve. The shape of the first shut-off element 7a may be configured to regulate the airflow through the vent line 7. More specifically, the actuator of the first shut-off element 7a may actuate the first shut-off element 7a to a fully closed position or a fully open position, or between the two positions. The fully closed position may correspond to the minimum amount of airflow through the first shut-off element (e.g., 0%), and the fully open position may correspond to the maximum amount of airflow through the first shut-off element (e.g., 100%). Therefore, actuating the first shut-off element between the fully closed and fully open positions also meters the amount of gas flowing through the first shut-off element 7a.

[0096] The bleed line 7 may merge with the first main exhaust line 6a to form a third main exhaust line 16 at junction 7c. The exhaust aftertreatment system 11 may be spaced around junction 7c such that a first three-way catalytic converter (TWC) 11a is positioned upstream of junction 7c in the first main exhaust line 6a, and a second TWC 11b is positioned downstream of junction 7c in the third main exhaust line 16. The first TWC 11a may be spaced from the second TWC 11b by a distance equal to the length of junction 7c. Alternatively, in one example, arranging the first TWC 11a and the second TWC 11b may allow exhaust from the bleed line 7 to flow only towards the second TWC 11b. Therefore, in one example, exhaust from the bleed line 7 may not flow towards the first TWC 11a. In this manner, the first TWC 11a may receive exhaust gas only from the first main exhaust line 6a, and the second TWC 11b may receive gas from both the first main exhaust line 6a and the vent line 7. As will be described below, the air and hydrocarbon concentrations of the gas from the vent line 7 may be higher than those of the gas from the first main exhaust line 6a.

[0097] Arranging the accumulator 12 allows exhaust gas to be captured in a closely coupled position during cold starts and / or warm-up phases. In one example, the accumulator 12 is an HC trap configured to store hydrocarbons (HC) dispersed in the exhaust gas. Hereinafter, the accumulator 12 may be interchangeably referred to as a hydrocarbon trap 12. More specifically, in some examples, the accumulator can store HC at a temperature below the ignition temperature of the first TWC 11a and the second TWC 11b. Therefore, in some examples, the first cut-off element 7a can be actuated based on the temperature of one or more of the engine 10 and the second TWC 11b, as referenced below. Figure 3A and Figure 3B As stated above.

[0098] In one example of a cold start, the vent line 7 is fluidly coupled to the second main exhaust line 6b by moving the first shut-off element 7a to a position that is at least partially open, and the accumulator 12 receives the exhaust gas. In some examples, the second shut-off element 6d (which may be substantially the same as the first shut-off element 7a in one or more of its shape and function) may be moved to a more closed or fully closed position to reduce the exhaust gas flow to the intake system 3. Thus, in one example, the second shut-off element 6d may be an EGR valve. The second shut-off element 6d is arranged downstream of the first junction 7b and downstream of the cooler 6c, and may also be used to set the amount of gas or exhaust gas for recirculation. Furthermore, when the first shut-off element 7a is at least partially open, exhaust gas discharge via the first main exhaust line 6a is prevented (i.e., prohibited). Figure 1A In embodiment 100, the first exhaust valve 4a is a switchable valve by equipping it with an actuator to prevent exhaust from being discharged via the first main exhaust line 6a. Each first exhaust valve 4a may be equipped with a clearance adjuster or a similar switching device configured to keep the valve closed.

[0099] Figure 1B The valve travel curves A1, A2, and E are shown during normal operation of the internal combustion engine 10 without a cold start. Figure 1C Valve travel curves A2 and E are depicted during cold start and / or warm-up phases.

[0100] In particular, Figure 1B The valve travel curve A1 of the first outlet valve 4a and the valve travel curve A2 of the second outlet valve 4b are shown. Figure 1A The valve travel curves E of inlet valves 2a and 2b.

[0101] In addition to the cold start of the engine 10, the first exhaust valve 4a can be actuated during the compression phase (e.g., exhaust stroke) before the top dead center (CE-TDC) of the charge exchange according to the valve travel curve A1 in order to discharge exhaust gas, and the inlet openings 2a and 2b open during the expansion phase (e.g., intake stroke) after the top dead center (CE-TDC) of the charge exchange according to the valve travel curve E in order to supply fresh boosted air to the cylinder 1.

[0102] The second exhaust valve 4b can be actuated according to the valve travel curve A2 when the associated cylinder of the three cylinders 1 transitions from the compression phase (e.g., exhaust stroke) to the expansion phase (e.g., intake stroke), wherein the maximum valve lift Δh of the second exhaust valve 4b is... max (For example, Δh2) is achieved at the top dead center (CE-TDC) of the inflation exchange. The maximum valve lift Δh of the second exhaust valve is... max It can be less than the maximum valve lift Δh of the first exhaust valve 4a. max(For example, Δh1) and the maximum valve lift Δh of intake valves 2a and 2b. max To prevent collision or contact with the piston. Exhaust air from cylinder 1, along with fresh air or boosted air, flows through the second exhaust valve 4b into the second main exhaust line 6b. This fresh air or boosted air, during the purification process, flows from the intake system 3 through inlet openings 2a and 2b into cylinder 1 and from cylinder 1 directly into the second main exhaust line 6b through the second outlet opening 4b. Based on the valve timing of the second exhaust valve 4b, the composition of the exhaust in the second main exhaust line 6b may differ from the composition of the exhaust in the first main exhaust line 6a. More specifically, the exhaust in the second main exhaust line 6b may contain a larger volume of air than the exhaust in the first main exhaust line.

[0103] The exhaust gas in the second main exhaust line 6b can be used for low-pressure exhaust gas recirculation (LP-EGR) or for release. Figure 1A The hydrocarbons stored in the accumulator 12. The utilization of the exhaust gas can be adjusted by actuating the first cut-off element 7a and the second cut-off element 6d, respectively. In some examples, the first cut-off element 7a can be actuated to the closed position when pressurization is desired. The second cut-off element 6d can be actuated to the closed position when EGR is not desired.

[0104] Specifically, Figure 1C It is shown that during the warm-up phase and / or cold start, the first outlet valve 4a is deactivated to prevent exhaust from being discharged via the first main exhaust line 6a, and the valve travel curve A1 is omitted.

[0105] Since no exhaust gas is discharged from cylinder 1 via the first main exhaust line 6a during the warm-up phase, the second outlet valve 4b reaches its maximum valve lift Δh during the compression phase (e.g., exhaust stroke). max And is correspondingly actuated for intake exchange. That is, during the compression phase of the associated cylinder 1, the second exhaust valve 4b is opened in each case.

[0106] Therefore, the second exhaust valve 4b may be equipped with a partially variable outlet valve and / or actuator, wherein the opening process can be advanced or delayed. Opening the second exhaust valve 4b results in the maximum valve lift Δh. max This is achieved in each case during the compression phase, such that the opening of the second outlet valve 4b and the intake valves 2a and 2b no longer overlap, and the second exhaust valve 4b is closed before CE-TDC. Therefore, the second main exhaust line 6b and the bleed line 7 can receive high-pressure exhaust during cold starts.

[0107] Therefore, based on the operation of the second exhaust valve 4b, the second main exhaust line 6b and the bleed line 7 can receive exhaust gas at higher or lower pressures. For example, during the cold start and / or warm-up phase of the engine 10, the second main exhaust line 6b and the bleed line 7 can receive exhaust gas at higher pressures containing less fresh air due to the earlier opening of the second exhaust valve 4b. Furthermore, the second shut-off element 6d is completely closed to prevent EGR flow. As another example, outside the cold start and / or warm-up phase of the engine 10, the second main exhaust line 6b can receive exhaust gas at lower pressures, which can be directed as LP-EGR to one or more of the intake systems 3, or directed to the bleed line 7 to release hydrocarbons from the accumulator 12.

[0108] Alternatively or concurrently, during certain engine conditions where the release of hydrocarbons stored in the accumulator 12 is desired or permissible, the second main exhaust line 6b may receive exhaust at lower pressure, and similar to... Figure 1B The valve travel curve A2, the valve timing of the second exhaust valve 4b can be delayed. This is in response to the second TWC being ignited (e.g., Figure 1A At the second TWC11b) temperature, hydrocarbon release can occur, wherein ignition involves a catalyst warmer than a threshold catalyst temperature, which is higher than the initial temperature at which hydrocarbons are stored in the HC trap, the threshold catalyst temperature being based on the catalyst temperature at which the catalyst can process the emissions in the presence of the desired compounds.

[0109] Therefore, unburned HC can Figure 1C In the case of valve actuation, the flow is directed to accumulator 12 and collected in accumulator 12. Once the second TWC (e.g., Figure 1A When the second TWC 11b) is ignited, the accumulated HC can be released. More specifically, engine operating conditions corresponding to the condition in which the accumulator 12 can release the HC accumulated thereon can include engine operating conditions other than cold start.

[0110] Figure 2A A second embodiment 200 of a supercharged internal combustion engine 10 is schematically shown. Its interpretation is solely related to... Figure 1A The differences related to the illustrated embodiment are referred to in other ways with reference to FIG1 for this reason. Therefore, the previously described components may be similarly numbered in this and subsequent drawings.

[0111] and Figure 1A The first embodiment 100 shown is the opposite. Figure 2AThe illustrated internal combustion engine 10 includes a third shut-off element 13 disposed in the exhaust system 5 upstream of the turbine 8a to prevent exhaust gas from being discharged via the first main exhaust line 6a. Therefore, in the second embodiment 200, the second exhaust valve 4a may not include an actuator configured to keep the second exhaust valve 4a closed. Alternatively, the third shut-off element 13 may be actuated to prevent exhaust gas from the first main exhaust line 6a from flowing to the third main exhaust line 16. The third shut-off element 13 may be substantially similar in function and / or shape to the first shut-off element 7a and the second shut-off element 6d.

[0112] Figure 2B It shows Figure 2A The valve travel curves during the warm-up phase of an internal combustion engine are shown.

[0113] Because the first exhaust valve 4a is not deactivated but remains activated during the warm-up phase, Figure 2B Valve travel curve A1 is not omitted.

[0114] However, since exhaust is not discharged from the first main exhaust line 6a via the exhaust system 5 during the warm-up phase, the second exhaust valve 4b can continue to be used and correspondingly actuated for similar purposes. Figure 1C The A2 shows the intake exchange. Therefore, due to the closure of the third cut-off element 13, exhaust gas can fill a portion of the first main exhaust line 6a without flowing to the turbine 8a, turbine bypass 9, and third main exhaust line 16. During cold starts, the second exhaust valve 4b can be opened during the compression phase of the associated cylinder 1, as shown... Figure 2B As shown.

[0115] Now go to Figure 3A and Figure 3B It shows a method for operation Figure 1A The method 300 for the exhaust valve of engine 10. This can be based on instructions stored in the controller's memory and combined with information from sensors in the engine system (such as those referenced below). Figure 4 The signals received by the described sensor are used by the controller to execute instructions for implementing method 300. According to the method described below, the controller can employ an engine actuator from the engine system to adjust engine operation.

[0116] Method 300 begins at 302, where it includes determining, estimating, and / or measuring current engine operating parameters. Current engine operating parameters may include, but are not limited to, one or more of throttle position, engine temperature, engine speed, manifold pressure, vehicle speed, exhaust gas recirculation rate, and air / fuel ratio.

[0117] Method 300 may proceed to 304, where it may include determining whether a cold start has occurred. A cold start may occur if the engine temperature is below a threshold temperature and / or below ambient temperature. The threshold temperature may be based on a desired engine operating range (e.g., 180℉ to 220℉). Alternatively or additionally, a cold start may occur if the catalyst (e.g., a first TWC 11a or a second TWC 11b) temperature is below the ignition temperature.

[0118] If a cold start occurs, method 300 can proceed to 306 to deactivate the first exhaust valve, which may be associated with the first main exhaust line. The first exhaust valve can be kept closed via, for example, an actuator or a hydraulic clearance adjuster, thereby preventing exhaust flow from the first exhaust valve to the second main exhaust line. In this way, exhaust gas may not flow from the cylinder to the turbine.

[0119] In some examples (such as) Figure 2A In the example of embodiment 200 shown, the first exhaust valve may not be coupled to an actuator configured to maintain the first exhaust valve in the closed position. However, a cut-off element (e.g., ...) arranged in the first main exhaust line may be used. Figure 2A The third cut-off element 13) is actuated to the fully closed position to prevent exhaust gas in the first main exhaust line from flowing to the turbine. Therefore, exhaust gas can fill a portion of the first main exhaust line between the third cut-off element and the cylinder without flowing to the turbine.

[0120] Method 300 may proceed to 308, where it may include advance opening of the second exhaust valve. Advance opening of the second exhaust valve during a cold start may be related to timing during engine operating conditions other than a cold start. This advance may reduce and / or prevent overlap between the opening of the second exhaust valve and the opening of the intake valve. More specifically, this advance may allow the second exhaust valve to open during the compression stroke and / or exhaust stroke of the cylinder, thereby allowing the second exhaust valve to allow higher-pressure exhaust gas to flow along with less fresh air into the second main exhaust line. In one example, this advance may be similar to... Figure 1C The timing of the second exhaust valve is shown.

[0121] Method 300 may proceed to 309, where it may include opening a first shut-off element and closing a second shut-off element. The first shut-off element may be arranged in a vent line downstream of the accumulator, and the second shut-off element may be arranged downstream of a first junction in the second main exhaust line and downstream of each of the coolers. Thus, exhaust flowing into the second main exhaust line may not flow into the intake system, but may only flow through the vent line and into the third main exhaust line.

[0122] Method 300 may proceed to 310, where it may include directing exhaust gas only to a bleed line to collect unburned fuel. By opening the second exhaust valve earlier, overlap between the second exhaust valve and the intake valve (which may be at least partially open) is avoided, thereby reducing the amount of fresh air flowing to the bleed line. The exhaust gas (which may contain unburned fuel) may flow to an accumulator (e.g., a hydrocarbon trap) arranged in the second exhaust line, whereby the hydrocarbon trap captures unburned fuel, thereby reducing emissions during cold starts.

[0123] Method 300 may proceed to 312, where it may include determining whether cold start has terminated. Cold start may terminate if the engine temperature is above a threshold temperature or ambient temperature. Alternatively, cold start may terminate if the three-way catalytic converter ignites. If cold start has not terminated, method 300 may proceed to 314 to continue operating under cold start conditions until the cold start conditions are no longer met.

[0124] However, if the cold start terminates or if the cold start does not occur as determined at 304, method 300 may proceed to Figure 3B 316.

[0125] At 316, method 300 may include enabling a first exhaust valve. Enabling the first exhaust valve may include allowing the first exhaust valve to be moved beyond a fully closed position, thereby disabling the actuator associated with the first exhaust valve. Alternatively or additionally, if the first exhaust valve does not include an actuator configured to keep the valve closed, a shut-off valve disposed in the first main exhaust line may be moved to a more open position to allow exhaust gas to flow through it.

[0126] Method 300 may proceed to 318, where it may include opening the first exhaust valve to its maximum opening Δh1 during the exhaust stroke. High-pressure exhaust gas may flow through the first main exhaust line, through the turbine, and through the remainder of the exhaust line to reach the ambient atmosphere. Alternatively or additionally, if a smaller pressure boost is desired, the exhaust gas may bypass the turbine via an actuated bypass valve and / or wastegate. In one example, opening the first exhaust valve may be similar to... Figure 1B The timing is shown.

[0127] Method 300 may proceed to 320, where it may include determining whether the second TWC has been ignited. As described above, the second TWC may be positioned downstream of a second junction where the first main exhaust line and the bleed line merge to form a third main exhaust line. The temperature of the second TWC may be estimated via feedback from a temperature sensor positioned near the second TWC (e.g., upstream, internally, or downstream). If the second TWC has not been ignited, method 300 may proceed to 322 to maintain current engine operating parameters and prevent gas flow to the bleed line. Method 300 may continue to monitor the temperature of the second TWC. If the second TWC has been ignited, making it catalytically active and capable of oxidizing hydrocarbons, method 300 may proceed to 324.

[0128] In some examples, the ignition temperature of the second TWC can be higher than the threshold release temperature of the accumulator. Therefore, it is desirable to coordinate the release of hydrocarbons stored in the accumulator with the ignition of the second TWC to reduce emissions. In some examples, a cold start can be completed before the second TWC is ignited. Exhaust can be diverted away from the vent line to prevent hydrocarbons from being released from the accumulator during the warm-up of the second TWC.

[0129] At 324, method 300 may include determining whether the accumulator temperature is greater than a threshold release temperature. As described above, there may be a period of time after the cold start ends and before the second TWC is ignited, during which gas does not flow to the accumulator in the bleed line, thereby allowing the accumulator to cool. Therefore, the accumulator temperature may decrease during said period and may drop well below the threshold release temperature, such that the timing of the first opening of the second valve (e.g., Figure 1B The mixture of exhaust and fresh air associated with the timing shown is too cold to adequately heat the accumulator to the threshold release temperature.

[0130] If the accumulator temperature is greater than the threshold release temperature, method 300 may proceed to 326 to delay the opening of the second exhaust valve. Delaying the opening of the second exhaust valve may include delaying the opening to a first timing, wherein the second exhaust valve reaches its maximum valve opening height during charge exchange. In some examples, the first timing is similar to that via... Figure 1B The timing of the second valve is shown by curve A2. Therefore, the first timing may include some overlap between the opening of the second exhaust valve and the opening of the intake valve.

[0131] Method 300 may proceed to 328, where a first mixture of gases may be directed toward an accumulator. The first mixture may comprise a first component of exhaust gas and fresh air, wherein the first component contains less exhaust gas and more fresh air than other mixtures flowing toward the accumulator. Additionally or alternatively, the pressure of the first component may be less than the pressure of other mixtures flowing toward the accumulator. Hydrocarbons may be released from the accumulator and directed to a second TWC located downstream of a second junction where the vent line and the first main exhaust line merge.

[0132] Method 300 may proceed to 330, where the released hydrocarbons may be oxidized in the second TWC. Oxidation is facilitated by the ignition of the second TWC combined with excess oxygen present therein.

[0133] Returning to 324, if the accumulator temperature is not greater than the threshold release temperature, then method 300 may proceed to 332 to advance the second exhaust valve opening. Advancing the second exhaust valve opening may include advancing the second exhaust valve opening to a second timing, which may include the second exhaust valve reaching its maximum valve opening height during the exhaust stroke prior to charge exchange. In some examples, the second timing may be substantially similar to... Figure 1C The second valve is open, as shown by curve A2 in the figure.

[0134] The method can proceed to 334 to allow a second mixture of gases to flow into the accumulator. The second mixture may contain a second component of exhaust gas and fresh air, wherein the second mixture contains more exhaust gas and less fresh air than other mixtures including the first mixture. By allowing more exhaust gas to flow, the temperature of the accumulator can increase more rapidly.

[0135] Alternatively or alternatively, increasing the flow of the second mixture may include adjusting one or more engine operating parameters to increase the air supply at the second TWC, said adjustment may include increasing the air / fuel ratio for leaner combustion. By doing so, hydrocarbons are incidentally released from the accumulator during accumulator warm-up, since hot spots, etc., can still be processed at the second TWC.

[0136] In some examples, additionally or alternatively, the second valve timing may be gradually delayed from the second timing to the first timing, allowing a gas mixture with a composition between the first and second mixtures to flow to the accumulator. In this way, more air and less exhaust gas can begin to flow to the accumulator before the accumulator temperature exceeds the threshold release temperature. This provides more uniform heating to the accumulator and increases the oxidation of hydrocarbons released from the accumulator.

[0137] In any case, method 300 can still continue to monitor the accumulator temperature similarly to method 324 after method 334.

[0138] Figure 4 An engine system 400 for a vehicle is depicted. The vehicle may be a road vehicle with drive wheels in contact with the road surface. The engine system 400 includes an engine 410, which includes a plurality of cylinders. Figure 4 A cylinder or combustion chamber of this type is described in detail. Various components of the engine 410 can be controlled via an electronic engine controller 412. In one example, the engine 410 can be... Figure 1A and Figure 2A The internal combustion engine 10 is used similarly.

[0139] Engine 410 includes a cylinder block 414 and a cylinder head 416. The cylinder block 414 includes at least one cylinder bore 20, and the cylinder head 416 may include an intake valve 152 and an exhaust valve 154. In other examples, where engine 410 is configured as a two-stroke engine, the cylinder head 416 may include one or more intake and / or exhaust ports. The cylinder block 414 includes a cylinder wall 32 having a piston 36 positioned therein and connected to a crankshaft 40. Thus, when coupled together, the cylinder head 416 and cylinder block 414 may form one or more combustion chambers. The capacity of the combustion chamber 30 is thus adjusted based on the oscillation of the piston 36. The combustion chamber 30 may also be referred to herein as a cylinder 30. The combustion chamber 30 shown communicates with an intake manifold 144 and an exhaust manifold 148 via corresponding intake valves 152 and exhaust valves 154. Each intake and exhaust valve can be operated by an intake cam 51 and an exhaust cam 53. Alternatively, one or more of the intake and exhaust valves can be operated via electromechanically controlled valve coils and armature assemblies. The position of the intake cam 51 can be determined via the intake cam sensor 55. The position of the exhaust cam 53 can be determined via the exhaust cam sensor 57. Thus, when valves 152 and 154 are closed, the combustion chamber 30 and cylinder bore 20 can be fluidly sealed, preventing gases from entering or leaving the combustion chamber 30. In one example, the intake valve 152 may be... Figure 1A and Figure 2A One or more of the intake valves 2a and 2b are used similarly. The exhaust valve 154 can be used with... Figure 1A and Figure 2A The first valve 4a or the second valve 4b is used similarly. More specifically, in Figure 4 In the example shown, the exhaust valve can be... Figure 1A and Figure 2A The first valve of the first valve 4a is used similarly.

[0140] Combustion chamber 30 may be formed by cylinder walls 32, piston 36, and cylinder head 416 of cylinder block 414. Cylinder block 414 may include cylinder walls 32, piston 36, crankshaft 40, etc. Cylinder head 416 may include one or more fuel injectors such as fuel injector 66, one or more intake valves 152, and one or more exhaust valves such as exhaust valve 154. Cylinder head 416 may be coupled to cylinder block 414 via fasteners such as bolts and / or screws. Specifically, when coupled, cylinder block 414 and cylinder head 416 may be in sealed contact with each other via gaskets, and thus cylinder block 414 and cylinder head 416 may seal combustion chamber 30 such that gases can only flow into and / or out of combustion chamber 30 via intake manifold 144 when intake valve 152 is open, and / or flow into and / or out of combustion chamber 30 via exhaust manifold 148 when exhaust valve 154 is open. In some examples, each combustion chamber 30 may include only one intake valve and one exhaust valve. However, in other examples, more than one intake valve and / or more than one exhaust valve may be included in each combustion chamber 30 of the engine 410. The turbine 164 may be... Figure 1A and Figure 2A The turbine 8a uses a similar design.

[0141] In some examples, each cylinder of engine 410 may include a spark plug 192 for initiating combustion. In a selected operating mode, ignition system 190 may provide an ignition spark to cylinder 30 via spark plug 192 in response to a spark advance signal SA from controller 412. However, in some embodiments, spark plug 192 may be omitted, such as in cases where engine 410 can initiate combustion by automatic ignition or by fuel injection, as is the case with some diesel engines.

[0142] Fuel injector 66 may be positioned to inject fuel directly into combustion chamber 30, a direct injection method known to those skilled in the art. Fuel injector 66 delivers liquid fuel in proportion to the pulse width of the signal FPW from controller 412. Fuel is delivered to fuel injector 66 via a fuel system (not shown), which includes a fuel tank, a fuel pump, and a fuel rail. Operating current from driver 68 is supplied to fuel injector 66 in response to controller 412. In some examples, engine 410 may be a gasoline engine, and the fuel tank may contain gasoline, which can be injected into combustion chamber 30 via injector 66. However, in other examples, engine 410 may be a diesel engine, and the fuel tank may contain diesel fuel, which can be injected into combustion chamber 30 via injector 66. Further, in such examples where engine 410 is configured as a diesel engine, engine 410 may include glow plugs to initiate combustion in combustion chamber 30.

[0143] The intake manifold 144 shown communicates with a throttle valve 62, which adjusts the position of a throttle plate 64 to control the airflow to the engine cylinders 30. This may include controlling the airflow from the intake boost chamber 146, which receives compressed air. In some embodiments, the throttle valve 62 may be omitted, and the airflow to the engine may be controlled via a single air intake system throttle valve (AIS throttle valve) 82 coupled to the air intake passage 42 and located upstream of the intake boost chamber 146. In another example, the AIS throttle valve 82 may be omitted, and the airflow to the engine may be controlled by the throttle valve 62.

[0144] In some embodiments, engine 410 is configured to provide exhaust gas recirculation (EGR). When EGR is included, it can be set to high-pressure EGR and / or low-pressure EGR. In an example where engine 410 includes low-pressure EGR, low-pressure EGR can be provided to the engine air intake system from a location downstream of turbine 164 in the exhaust system via EGR passage 135 and EGR valve 138 at a location downstream of air intake system (AIS) throttle valve 82 and upstream of compressor 162. EGR can be drawn from the exhaust system into the intake system when a pressure differential driving the flow is present. The pressure differential can be created by partially closing AIS throttle valve 82. Throttle plate 84 controls the pressure at the inlet of compressor 162. AIS can be electrically controlled and its position can be adjusted based on optional position sensor 88.

[0145] Ambient air is drawn into combustion chamber 30 via intake passage 42, which includes air filter 156. Thus, air first enters intake passage 42 through air filter 156. Compressor 162 then draws air from intake passage 42 to supply compressed air to boost chamber 146 via compressor outlet pipe (not shown in FIG. 1). In some examples, intake passage 42 may include an airbox (not shown) with a filter. In one example, compressor 162 may be a turbocharger, wherein power to compressor 162 is drawn from the exhaust flow via turbine 164. Specifically, exhaust can rotate turbine 164, which is coupled to compressor 162 via shaft 161. Exhaust valve 72 allows exhaust to bypass turbine 164, enabling boost control under different operating conditions. Exhaust valve 72 may be closed (or its opening may be reduced) in response to increased boost demand, such as during operator depressing the accelerator pedal. By closing the wastegate, the exhaust pressure upstream of the turbine can be increased, thereby increasing turbine speed and peak power output. This allows for a rise in boost pressure. Alternatively, when the compressor recirculation valve is partially open, the wastegate can be moved toward the closed position to maintain the desired boost pressure. In another example, the wastegate 72 can be opened (or the wastegate opening can be increased) in response to reduced boost demand, such as when the operator depresses the accelerator pedal. By opening the wastegate, the exhaust pressure is reduced, thereby reducing turbine speed and turbine power. This allows for a decrease in boost pressure.

[0146] However, in an alternative embodiment, compressor 162 may be a mechanical supercharger, wherein power to compressor 162 is drawn from crankshaft 40. Therefore, compressor 162 may be coupled to crankshaft 40 via a mechanical linkage such as a belt. Thus, a portion of the rotational energy output from crankshaft 40 may be transferred to compressor 162 to power compressor 162.

[0147] A compressor recirculation valve 158 (CRV) may be disposed in a compressor recirculation path 159 surrounding compressor 162, allowing air to move from compressor outlet to compressor inlet to reduce the pressure that may be generated on both sides of compressor 162. A boost air cooler 157 may be positioned in a boost chamber 146 downstream of compressor 162 to cool the boosted air delivered to the engine intake system. However, in other examples as shown in FIG1, the boost air cooler 157 may be positioned downstream of electronic throttle valve 62 in intake manifold 144. In some examples, boost air cooler 157 may be an air-to-air boost air cooler. However, in other examples, boost air cooler 157 may be a liquid-to-air cooler.

[0148] In the depicted example, compressor recirculation path 159 is configured to recirculate cooled compressed air from upstream of booster air cooler 157 to the compressor inlet. In an alternative example, compressor recirculation path 159 may be configured to recirculate compressed air from downstream of the compressor and downstream of booster air cooler 157 to the compressor inlet. CRV 158 can be opened and closed via an electrical signal from controller 412. CRV 158 may be configured as a three-state valve capable of moving to a default half-open position or a fully open position.

[0149] The universal exhaust oxygen (UEGO) sensor 126 shown is coupled to the exhaust manifold 148 upstream of the emission control unit 70. Alternatively, a dual-state exhaust oxygen sensor may replace the UEGO sensor 126. In one example, the emission control unit 70 may include multiple catalyst blocks. In another example, multiple emission control units, each having multiple blocks, can be used. Although the depicted example shows the UEGO sensor 126 upstream of the turbine 164, it should be understood that in alternative embodiments, the UEGO sensor may be located downstream of the turbine 164 or upstream of the emission control unit 70 in the exhaust manifold. Additionally or alternatively, the emission control unit 70 may include a diesel oxidation catalyst (DOC) and / or a diesel cold start catalyst, a particulate filter, a three-way catalytic converter, and a NO... x The device includes a trap, a selective catalytic reduction unit, and combinations thereof. In some examples, sensors may be positioned upstream or downstream of the emission control unit 70, wherein the sensors may be configured to diagnose the state of the emission control unit 70.

[0150] Controller 412 in Figure 4The computer is shown as a microcomputer and includes: a microprocessor unit (CPU) 102, an input / output port (I / O) 104, a read-only memory (ROM) 106, a random access memory (RAM) 108, a keep-alive memory (KAM) 110, and a conventional data bus. The controller 412 shown receives various signals from sensors coupled to the engine 410, including, in addition to those previously discussed: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling manifold 114; position sensor 134 coupled to input device 130 for sensing input device pedal position (PP) adjusted by vehicle operator 132; knock sensor (not shown) for determining exhaust ignition; engine manifold pressure (MAP) measurement from pressure sensor 121 coupled to intake manifold 144; boost pressure measurement from pressure sensor 122 coupled to boost chamber 146; engine position sensor from Hall effect sensor 118 sensing crankshaft 40 position; mass of air entering the engine from sensor 120 (e.g., hot-wire flow meter); and throttle position measurement from sensor 58. Atmospheric pressure (sensor not shown) may also be sensed for processing by controller 412. In a preferred aspect of this specification, the Hall effect sensor 118 generates a predetermined number of equally spaced pulses during each rotation of the crankshaft, enabling the determination of the engine speed (RPM) via these pulses. The input device 130 may include an accelerator pedal and / or a brake pedal. Therefore, the output from the position sensor 134 can be used to determine the position of the accelerator pedal and / or brake pedal of the input device 130, and thus determine the desired engine torque. Therefore, the desired engine torque, as requested by the vehicle operator 132, can be estimated based on the pedal position of the input device 130.

[0151] In some examples, vehicle 405 may be a hybrid vehicle having multiple torque sources available for one or more wheels 59. In other examples, vehicle 405 may be a conventional vehicle with only an engine or an electric vehicle with only one or more electric motors. In the illustrated example, vehicle 405 includes an engine 410 and an electric motor 52. The electric motor 52 may be a motor or a motor / generator. When one or more clutches 56 are engaged, the crankshaft 40 of engine 410 and the electric motor 52 are connected to the wheels 59 via a transmission 54. In the depicted example, a first clutch 56 is disposed between the crankshaft 40 and the electric motor 52, and a second clutch 56 is disposed between the electric motor 52 and the transmission 54. A controller 412 may send signals to the actuators of each clutch 56 to engage or disengage the clutch, thereby connecting or disconnecting the crankshaft 40 from the electric motor 52 and components connected to the electric motor 52, and / or connecting or disconnecting the electric motor 52 from the transmission 54 and components connected to the transmission 54. The transmission 54 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain can be configured in various ways, including in hybrid vehicles configured as parallel, series, or series-parallel.

[0152] Electric motor 52 receives power from traction battery 58 to provide torque to wheel 59. Electric motor 52 can also be operated as a generator to provide power, for example, during braking operations, to charge battery 58.

[0153] Controller 412 from Figure 4 Various sensors receive signals and employ Figure 4 Various actuators adjust engine operation based on received signals and instructions stored in the controller's memory. For example, adjustment of the electric motor 52 can occur based on feedback from the ECT sensor 112. As will be described in more detail below, the operation of the engine 410 and the electric motor 52 can be delayed based on one or more of the powertrain temperature (estimated based on feedback from the ECT sensor 112) and the distance between the expected destination and the pure electric operating range.

[0154] In this way, the engine exhaust system can be divided into a first main exhaust line and a second main exhaust line, which are fluidly coupled to a first exhaust valve and a second exhaust valve, respectively. The first and second main exhaust lines can be separated, wherein the first main exhaust line may include a turbine, and wherein the second main exhaust line may include a low-pressure exhaust gas recirculation valve. A bleed line can branch off from the second main exhaust line, allowing an accumulator disposed in the bleed line to be closely coupled to the engine. The technical advantage of arranging the accumulator in a closely coupled position to the engine is that emissions during engine cold starts are reduced by directing exhaust flow to the second main exhaust line and into the bleed line, rather than allowing exhaust to flow as low-pressure EGR or into the first main exhaust line. By doing so, hydrocarbons in the accumulator can be stored and released as needed during engine operating conditions where the three-way catalytic converter oxidizes hydrocarbons.

[0155] An embodiment of a mechanically supercharged internal combustion engine with applied ignition has three cylinders arranged in an inline. The internal combustion engine includes at least one inlet opening shaped to receive pressurized air from an intake system and at least two outlet openings shaped to discharge exhaust gas to an exhaust system (each outlet opening is adjacent to a separate exhaust line), at least one exhaust turbocharger including a turbine arranged in the exhaust system and a compressor arranged in the intake system, the separate exhaust lines being shaped into a first group and a second group, and wherein the first group and the second group include at least one exhaust line from each cylinder. In each case where the two separate exhaust manifolds are formed, the exhaust lines of each group merge to form a first main exhaust line and a second main exhaust line spaced apart from each other. The first main exhaust line of the first group leads to a turbine upstream of the exhaust aftertreatment system, and the second main exhaust line of the second group leads to an intake system upstream of the compressor. A bleed line branches off from the second main exhaust line to form a first junction. The bleed line includes a cut-off element downstream of an accumulator shaped to trap hydrocarbons. The bleed line merges with the first main exhaust line at a second junction downstream of the cut-off element to form a third main exhaust line. A first example of a supercharged engine further includes an outlet opening corresponding to the first main exhaust line having a larger diameter than the outlet opening corresponding to the second main exhaust line. A second example of a supercharged engine (optionally including the first example) further includes an exhaust aftertreatment system comprising a first aftertreatment unit and a second aftertreatment unit, and a second junction located upstream of the second aftertreatment unit of the exhaust aftertreatment system, the second aftertreatment unit being arranged in the third main exhaust line. A third example of a supercharged engine (optionally including the first and / or second examples) further includes a first aftertreatment device and a second aftertreatment device being a three-way catalytic converter. A fourth example of a supercharged engine (optionally including one or more of the first to third examples) further includes a first cut-off element, and a first main exhaust line further includes a second cut-off element disposed upstream of the turbine. A fifth example of a supercharged engine (optionally including one or more of the first to fourth examples) further includes an outlet opening corresponding to the first main exhaust line, each equipped with at least partially variable-actuated outlet valves configured to hold the outlet openings in a closed position. A sixth example of a supercharged engine (optionally including one or more of the first to fifth examples) further includes an exhaust gas recirculation valve disposed in a second main exhaust line downstream of the first junction. A seventh example of a supercharged engine (optionally including one or more of the first to sixth examples) further includes a cooler disposed in a second main exhaust line downstream of the first junction.

[0156] An embodiment of the system includes a turbocharged engine comprising a plurality of cylinders, each of the plurality of cylinders including a first exhaust valve of a plurality of first exhaust valves and a second exhaust valve of a plurality of second exhaust valves, a first main exhaust line fluidly coupled to the plurality of first exhaust valves, and a second main exhaust line fluidly coupled to the plurality of second exhaust valves, a bleed line branching off from the second main exhaust line at a first junction upstream of an LP-EGR valve disposed in the second main exhaust line, and wherein the bleed line includes a hydrocarbon trap (the trap being tightly coupled to the engine upstream of a second junction where the bleed line merges with the first main exhaust line to form a third main exhaust line), and The system includes a second engagement point located downstream of the turbine in the first main exhaust line and a controller having computer-readable instructions stored in its non-transitory memory that, when executed, enable the controller to open multiple second exhaust valves in response to a cold start delay to allow a first mixture of gases to flow toward a hydrocarbon trap and a portion of the second main exhaust line downstream of the first engagement point toward the LP-EGR valve. The multiple first exhaust valves oscillate between open and closed positions, and in response to a cold start, advance the opening of the multiple second exhaust valves to allow a second mixture of gases to flow only toward the hydrocarbon trap. The multiple first exhaust valves remain closed for the duration of the cold start. A first example of the system also includes a first mixture of gases containing less exhaust gas and more fresh air than a second mixture of gases. A second example of the system (optionally including the first example) also includes a first main exhaust line fluidly separated from a second main exhaust line. A third example of the system (optionally including the first and / or second examples) further includes an aftertreatment system comprising a first three-way catalyst and a second three-way catalyst, wherein the first three-way catalyst is disposed upstream of a second junction in a first main exhaust line, and the second three-way catalyst is disposed downstream of a second junction in a third main exhaust line. A fourth example of the system (optionally including one or more of the first to third examples) further includes releasing hydrocarbons from a hydrocarbon trap to which the exhaust flows in response to one or more of the second three-way catalyst being ignited and the hydrocarbon trap temperature being greater than a threshold release temperature. A fifth example of the system (optionally including one or more of the first to fourth examples) further includes a plurality of first exhaust valves comprising a maximum opening height Δh1, and a plurality of second exhaust valves comprising a maximum opening height Δh2, wherein Δh1 is greater than Δh2.

[0157] Embodiments of the engine method include adjusting the airflow to an accumulator arranged in a bleed line fluidly coupled to each of a first main exhaust line and a second main exhaust line, wherein the first main exhaust line is fluidly coupled to a plurality of first exhaust valves and the second main exhaust line is fluidly coupled to a plurality of second exhaust valves, wherein the first and second main exhaust lines are fluidly spaced apart, thereby allowing a first mixture of gases to flow to the accumulator outside of a cold start by delaying the opening of the plurality of second exhaust valves to achieve an overlap between the opening of the plurality of second exhaust valves and the opening of one or more intake valves, and allowing a second mixture of gases to flow to the accumulator during a cold start by advancing the opening of the plurality of second exhaust valves to reduce the overlap between the opening of the plurality of second exhaust valves and the opening of one or more intake valves. A first example of the method further includes wherein the maximum opening height of the plurality of second exhaust valves is less than the maximum opening height of the plurality of first exhaust valves, and wherein the diameter of each of the plurality of second exhaust valves is less than the diameter of each of the plurality of first exhaust valves. A second example of the method (optionally including the first example) further includes wherein the first mixture contains less exhaust gas and more fresh air than the second mixture. A third example of the method (optionally including the first and / or second examples) further includes a turbine upstream of the junction of the first main exhaust line and the bleed line, and an exhaust gas recirculation valve downstream of the bleed line where it branches off from the second main exhaust line, and cold start further includes directing a second mixture of gases only to the accumulator and not to the turbine and the exhaust gas recirculation valve. A fourth example of the method (optionally including one or more of the first to third examples) further includes a three-way catalyst disposed downstream of the junction where the bleed line and the first main exhaust line merge, and hydrocarbons stored in the accumulator are released in response to the temperature of the three-way catalyst. A fifth example of the method (optionally including one or more of the first to fourth examples) further includes exhaust gas in the first main exhaust passage not mixing with exhaust gas in the second main exhaust passage.

[0158] Note that the example control and estimation programs included herein can be used with various engine and / or vehicle system configurations. The control methods and programs disclosed herein can be stored as executable instructions in non-transitory memory and can be implemented by a control system including a controller in combination with various sensors, actuators, and other engine hardware. The specific programs described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, etc. Therefore, the various actions, operations, and / or functions shown can be executed in the order shown, in parallel, or omitted in some cases. Similarly, the order of processing is not necessary to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the shown actions, operations, and / or functions can be repeatedly executed according to the specific strategy used. Furthermore, the described actions, operations, and / or functions can be graphically represented as code to be programmed into the non-transitory memory of a computer-readable storage medium in an engine control system, wherein the described actions are implemented by combining instructions executed by an electronic controller in a system including various engine hardware components.

[0159] It should be understood that because many variations are possible, the configurations and procedures disclosed herein are exemplary in nature, and these specific embodiments should not be considered limiting. For example, the above-described techniques can be applied to V-6, I-4, I-6, V-12, opposed 4-cylinder, and other engine types. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations disclosed herein, as well as other features, functions, and / or properties.

[0160] The appended claims specifically point to certain combinations and sub-combinations that are considered novel and non-obvious. These claims may refer to an “a” element or a “first” element or its equivalents. Such claims should be understood to include combinations of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or properties may be claimed by amendments to the claims of this application or by setting new claims in this application or related applications. Such claims, whether broader, narrower, equal to, or different from the scope of the initial claims, are also considered to be included within the subject matter of this disclosure.

Claims

1. A mechanically supercharged, spark applied, internal combustion engine having three cylinders in an inline arrangement, wherein the internal combustion engine comprises: each cylinder having at least one inlet opening shaped to receive supercharged air from an intake system and at least two outlet openings shaped to discharge exhaust gas to an exhaust discharge system, each outlet opening being contiguous with a separate exhaust line; at least one exhaust turbocharger comprising a turbine arranged in the exhaust discharge system and a compressor arranged in the intake system; the separate exhaust lines being shaped into a first group and a second group, and wherein the first group and the second group comprise at least one exhaust line from each cylinder, wherein the exhaust lines of each group are merged in each case where two separate exhaust manifolds are formed to form a first and a second total exhaust line, the first and the second total exhaust line being separated from each other, wherein the first total exhaust line of the first group leads to the turbine upstream of an exhaust aftertreatment system, and wherein the second total exhaust line of the second group leads to the intake system upstream of the compressor; a bleed line branches off from the second total exhaust line to form a first junction, the bleed line comprising a shut-off element downstream of an accumulator shaped to trap hydrocarbons, the bleed line merging with the first total exhaust line at a second junction downstream of the shut-off element to form a third total exhaust line; and during a cold start, the outlet openings contiguous with the exhaust lines of the second group are opened early.

2. The mechanically supercharged, spark applied, internal combustion engine of claim 1, wherein the outlet openings corresponding to the first total exhaust line comprise a larger diameter than the outlet openings corresponding to the second total exhaust line.

3. The mechanically supercharged, spark applied, internal combustion engine of claim 1, wherein the exhaust aftertreatment system comprises a first and a second aftertreatment device, and wherein the second junction is located upstream of the second aftertreatment device of the exhaust aftertreatment system, the second aftertreatment device being arranged in the third total exhaust line.

4. The mechanically supercharged, spark applied, internal combustion engine of claim 3, wherein the first and the second aftertreatment device are three-way catalysts.

5. The mechanically supercharged, spark applied, internal combustion engine of claim 1, wherein the shut-off element is a first shut-off element, and wherein the first total exhaust line further comprises a second shut-off element arranged upstream of the turbine.

6. The mechanically supercharged, spark applied, internal combustion engine of claim 1, wherein the outlet openings corresponding to the first total exhaust line are each equipped with an at least partially variably actuated outlet valve configured to hold the outlet opening in a closed position.

7. The mechanically supercharged, spark applied, internal combustion engine of claim 1, wherein an exhaust gas recirculation valve is arranged in the second total exhaust line downstream of the first junction.

8. The mechanically supercharged fired internal combustion engine of claim 7, wherein a cooler is arranged in the second common exhaust line downstream of the first junction.

9. A system for a vehicle, comprising: a turbocharged engine including a plurality of cylinders, wherein each cylinder of the plurality of cylinders includes a first exhaust valve of a plurality of first exhaust valves and a second exhaust valve of a plurality of second exhaust valves; a first common exhaust line fluidly coupled to the plurality of first exhaust valves and a second common exhaust line fluidly coupled to the plurality of second exhaust valves; a bleed line branching from the second common exhaust line at a first junction upstream of an LP-EGR valve arranged in the second common exhaust line, and wherein the bleed line includes a hydrocarbon trap fluidly coupled to the engine upstream of a second junction at which the bleed line merges with the first common exhaust line to form a third common exhaust line, and wherein the second junction is downstream of a turbine arranged in the first common exhaust line; and a controller having computer readable instructions stored on a non-transitory memory thereof that, when executed, enable the controller to: in response to a cold start being completed, delay opening of the plurality of second exhaust valves to flow a first mixture of gases toward the hydrocarbon trap and a portion of the second common exhaust line downstream of the first junction toward the LP-EGR valve, and wherein the plurality of first exhaust valves oscillate between an open position and a closed position; and in response to a cold start, advance opening of the plurality of second exhaust valves to flow a second mixture of gases only toward the hydrocarbon trap, and wherein the plurality of first exhaust valves remain closed for a duration of the cold start.

10. The system of claim 9, wherein the first mixture of gases includes less exhaust gas and more fresh air than the second mixture of gases.

11. The system of claim 9, wherein the first common exhaust line is fluidly isolated from the second common exhaust line.

12. The system of claim 9, further comprising an aftertreatment system including a first three-way catalyst and a second three-way catalyst, and wherein the first three-way catalyst is arranged upstream of the second junction in the first common exhaust line and the second three-way catalyst is arranged downstream of the second junction in the third common exhaust line.

13. The system of claim 12, wherein the hydrocarbon trap releases hydrocarbons from an exhaust stream flowing thereto in response to one or more of the second three-way catalyst being light-off and a temperature of the hydrocarbon trap being greater than a threshold release temperature.

14. The system of claim 9, wherein the first plurality of exhaust valves comprises a maximum opening height Ahl, and wherein the second plurality of exhaust valves comprises a maximum opening height Ah2, and wherein Ahl is greater than Ah2.

15. An engine method comprising: flowing exhaust to one or more of: a first common exhaust line, a second common exhaust line separate from the first common exhaust line, a bleed line, wherein the first common exhaust line is capable of receiving the exhaust via first exhaust valves of a cylinder, the second common exhaust line is capable of receiving the exhaust via second exhaust valves of the cylinder, the bleed line branches off from the second common exhaust line; and adjusting an amount of fresh air in the bleed line that flows to an HC accumulator disposed in the bleed line in response to an accumulator temperature, comprising: delaying opening of the second exhaust valves in response to the accumulator temperature being greater than a threshold release temperature; advancing opening of the second exhaust valves in response to the accumulator temperature not being greater than the threshold release temperature.

16. The method of claim 15, wherein a maximum opening height of the second exhaust valves is less than a maximum opening height of the first exhaust valves, and wherein a diameter of each of the second exhaust valves is less than a diameter of each of the first exhaust valves.

17. The method of claim 15, wherein delaying opening of the second exhaust valves causes less exhaust and more fresh air to flow to the HC accumulator than advancing opening of the second exhaust valves.

18. The method of claim 15, wherein the first common exhaust line comprises a turbine upstream of a location where the first common exhaust line and the bleed line merge, and wherein the second common exhaust line comprises an exhaust gas recirculation valve downstream of a location where the bleed line branches off from the second common exhaust line.

19. The method of claim 15, wherein a three-way catalyst is disposed downstream of a junction at which the bleed line and the first common exhaust line merge, and wherein hydrocarbons stored on the accumulator are released in response to a temperature of the three-way catalyst.

20. The method of claim 15, wherein exhaust in the first common exhaust line is not mixed with exhaust in the second common exhaust line.

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